=================================================================
Logtalk - Object oriented extension to Prolog
Release 2.22.4

Copyright (c) 1998-2005 Paulo Moura.  All Rights Reserved.
=================================================================


% start by loading the example:

| ?- logtalk_load(dcgs(loader)).
...


% DCG rules implementing a simple calculator:

| ?- calculator::parse("1+2-3*4", Result).

Result = -9
yes


% recognizing gramatically correct sentences:

| ?- sentence::parse([the, girl, likes, the, boy], Result).

Result = true
yes

| ?- sentence::parse([the, girl, scares, the, boy], Result).

Result = false
yes


% generating parse trees for sentences:

| ?- parsetree::parse([the, girl, likes, the, boy], Tree).

Tree = s(np(d(the), n(girl)), vp(v(likes), np(d(the), n(boy))))
yes


% bill of materials example:

| ?- bom::parts(bike, L).

L = [frame, crank, pedal, pedal, chain, spokes, rim, hub, spokes, rim, hub]
yes

| ?- bom::parts(wheel, L).

L = [spokes, rim, hub]
yes


% parsing command-line shell input:

| ?- shell::parse("pwd; cd ..; ls -a", L).

L = [pwd,'cd ..','ls -a'] ? 

yes


% walker movements:

| ?- walker::walk([n(5), e(4), s(2), nw(8), s(5), se(1), n(4)], Ending).

Ending = -0.94974746830583223,6.9497474683058318 ? 

yes


% conversion between compound terms and XML:

| ?- xml::convert(word(child, children), word(singular, plural), XML).

XML = '<word><singular>child</singular><plural>children</plural></word>' 
yes

| ?- xml::convert(Term, Interpretation, '<word><singular>child</singular><plural>children</plural></word>').

Term = word(child, children)
Interpretation = word(singular, plural) 
yes


% parsing URLs:

| ?- url::parse("http://www.logtalk.org", Components).

Components = [protocol(http), address([www, logtalk, org]), path([]), file('')] 
yes

| ?- url::parse("http://www.logtalk.org/", Components).

Components = [protocol(http), address([www, logtalk, org]), path(['']), file('')] 
yes

| ?- url::parse("http://www.logtalk.org/cvs", Components).

Components = [protocol(http), address([www, logtalk, org]), path([cvs]), file('')] 
yes

| ?- url::parse("http://www.logtalk.org/cvs.html", Components).

Components = [protocol(http), address([www, logtalk, org]), path([]), file('cvs.html')] 
yes

| ?- url::parse("http://193.136.64.5/files/update", Components).

Components = [protocol(http), address([193, 136, 64, 5]), path([files, update]), file('')] 
yes


% command language example:

| ?- faa::main.
Fly Amzi! Air
enter command> list flights
aa101
aa102
aa103
enter command> book elana aa102
enter command> book tom aa102
enter command> list passengers aa102
elana
tom
enter command> exit
yes


% double bypass using the {}/1 control constructs of grammar rules and Logtalk:

| ?- bypass::phrase(foo, _, _).

bar predicate called
yes


% run the Logtalk DCG translator on the test cases:

| ?- dcgtest::run.

...